Timing Spike at WOT
04-04-2009, 01:53 PM
#1
Timing Spike at WOT More wacky problems from this same car that will not return to idle routines 100% of the time.
Here's the latest. We took it to the track and were doing some nitrous shakedown passes on a small shot. He made a pass and burned off all but 2 of the straps on the plugs. I look at the log and at about 6K RPM timing jumps from the flat commanded 13* to a solid 29*. First thing I checked was to make sure that there was no modifier table screwing me up. The IAT sensor is tricked to read 73* temp all the time. ECT temp was solid 190-205*. TPS read 100% throughout the entire pass.
There are only 3 tables that show 29* timing in that region of cylinder airmass (0.80 and up). The park and drive idle tables and the max torque table. Only the torque table goes up to 8K RPM. I changed the torque table to 14* and the idle tables to 12* in order to see which one it is. We changed plugs and did a few blasts on the street but it never fluctuated from 13*.
How does this max torque timing table work? Is there a way that I can identify which table is in use while scanning (besides what I already did)?
This is a 99 F-body tuned in Open loop MAF w/ HPTuners. It is a wet direct port shot.
Here's the latest. We took it to the track and were doing some nitrous shakedown passes on a small shot. He made a pass and burned off all but 2 of the straps on the plugs. I look at the log and at about 6K RPM timing jumps from the flat commanded 13* to a solid 29*. First thing I checked was to make sure that there was no modifier table screwing me up. The IAT sensor is tricked to read 73* temp all the time. ECT temp was solid 190-205*. TPS read 100% throughout the entire pass.
There are only 3 tables that show 29* timing in that region of cylinder airmass (0.80 and up). The park and drive idle tables and the max torque table. Only the torque table goes up to 8K RPM. I changed the torque table to 14* and the idle tables to 12* in order to see which one it is. We changed plugs and did a few blasts on the street but it never fluctuated from 13*.
How does this max torque timing table work? Is there a way that I can identify which table is in use while scanning (besides what I already did)?
This is a 99 F-body tuned in Open loop MAF w/ HPTuners. It is a wet direct port shot.
04-07-2009, 07:28 AM
#4
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I had a problem with my timing spiking up at wot. It was caused by my tb overextending the TPS beyond 100%. Once it extends past 100% it goes into another timing map and adds alot of timing.
04-07-2009, 12:43 PM
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I know it leaned the heck out of the air/fuel and added a bunch of timing and made it spark knock like a bitch at WOT. Thats all I know. Slowhawk figured it out.
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04-08-2009, 09:13 AM
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It was a poor design in he linkage on my TB that was turning the TPS past 100%. at W.O.T. He adjusted my TB linkage and slotted my tps holes so it could be adjusted.
04-08-2009, 01:56 PM
#9
Thanks for the info. We are doing some testing right now. We are seeing 100% TPS at 4.0v and the blade is not all the way open. The TPS voltage goes up to 4.73 at true WOT without the solonoids being on. When we activate the nitrous it kicks on at 4.25v but goes up to 4.80v at true WOT. If we hold the pedal down without the noids on we see 4.73v and as soon as the nitrous activates, it jumps to 4.8v everytime. There has to be something going on with the eletronic throttle switch causing the issue as it hasn't happened yet on motor. We are going to try removing the TPS from the equation and using a microswitch behind the pedal.